改性生物炭对汞污染土壤黄瓜生长及品质的影响研究

Effects of applying modified biochar on growth andquality of cucumber in Hg-contaminated soil

为了探究改性生物炭对汞矿区土壤植物生长及品质的影响,采集陕西旬阳汞矿区的污染土壤,采用改性生物炭的不同添加比例进行黄瓜盆栽试验,分别设置0(CK)、10(T10)、30 g·1.5kg^(-1)(T30)和50 g·1.5kg^(-1)(T50)4种处理,测定了黄瓜的生长、生理指标以及各器官的汞及微量元素含量。试验结果表明,T10处理时,黄瓜根的干质量较CK提高了100%,对茎叶的生物量无显著影响,T30和T50处理黄瓜各部分的干质量均显著降低。T10、T30、T50处理使黄瓜果实的汞含量较CK分别降低了70%、62%、65%。T30和T50处理提高了黄瓜果实中的抗坏血酸和硝酸盐含量,导致叶片POD活性降低了59.8%和66.7%,CAT活性降低了16.2%和16.1%。T10处理在汞元素固化效果、黄瓜生物量及营养品质等方面表现最优,对土壤环境和黄瓜自身的生长发育影响较小。可见,较低浓度的改性生物炭可用于汞污染地区生态修复治理及作物营养调控。

This study used contaminated soil samples collected from the Xunyang Hg mining area in Shaanxi Province to examine the effects of modified biochar on plant growth and quality in the Hg mining areas.Cucumber potted planting experiments were carried out using different amount of modified biocarbon additions.Four treatments were set:0 g·1.5kg^(-1)(CK),10 g·1.5kg^(-1)(T10),30 g·1.5kg^(-1)(T30)and 50 g·1.5kg^(-1)(T50)respectively.The growth,physiological indicators and Hg and trace element concentration of each organ were determined.The experimental results showed that the dry mass of cucumber roots treated with T10 increased by 100%compared with CK,but there was no significant effect on stems and leaves.The dry mass of cucumber organs in T30 and T50 treatments decreased significantly.The Hg concentration of cucumber fruits treated with T10,T30 and T50 decreased by 70%,62%and 65%respectively compared with CK.T30 and T50 treatments increased ascorbic acid and nitrate contents in cucumber fruits,leading to a decrease of 59.8%and 66.7%in leaf POD activity,and a decrease of 16.2%and 16.1%in CAT activity.T10 treatment had the best performance in several aspects such as Hg curing effect,cucumber nutritional quality and biomass,and had less impact on growth and development of soil and environmental cucumber itself.The findings suggest that low concentration of modified biochar can be used for ecological restoration and crop nutrition regulation in the Hg-contaminated areas.